Black sulfur dye.



RICHARD KIRCHHOFF AND EMIL HA-U SSMA NN, OF BERLIN, GERMANY, AS-

SIGNORS TO THE ACTIEN-GESELLSCHAFT FUR OF SAME PLACE.

ANILIN FABRIKATION,

BLACK SULFUR DYE.

SPECIFICATION forming part of Letters Patent No. 647,846, dated April 1'7, 1900.

Application filed January 9,1900. Serial No. 869. (No specimens.)

To all whom it may concern:

Be it known that we, RICHARD KIRCHHOFF and EMIL HAUSSMANN, of Berlin, in the Kingdom of Prussia, German Empire, have inven ted new and useful Improvements in the Production of Black Dye; and we do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others. skilled in the art to which it appertains to make and use the same.

This invention relates to the production of a black sulfureted coloring-matter directly dyeing cotton and is based upon the following observations.

To have discovered that by melting an equimolecular mixture of dinitrooxydiphenylamin NOn and dinitrophenol: (I)H 2 .called immedial black, obtained by melting with sulfur and sulfids of alkali metals dinitrooxydiphenylamin and of the dyesufi which results from melting with sulfur and sulfids of alkali metals dinitrophenol alone, (compare United States Letters Patent No.

618,152, of 1899;) but as the new coloring-mat ter essentially differs by its properties from both these dyestuffs and as besides it has been found impossible to arrive at a similar product by simply mixing both the dyestuffs above mentioned there is no doubt that a new and uniform compound has been formed in which dinitrophenol as well as dinitrooxydiphenylamin have entered into combination with one another and with sulfur.

To further illustrate our invention, we give the following example: One hundred and seventy kilos of sodium sulfid, sixty kilos of sulfur, and fifteen kilos of water are heated up to and a mixture of twenty kilos of dinitrooxydiphenylamin and 13.2 kilos of dinitrophenol are slowly added thereto. The temperature is then brought first to After sometime it is slowly raised, and it is maintained at last at to until a sample proves that the formation of dyestuff does no more increase.

The dyestuff may be rendered ready for technical use by several ways. Either the product of the reaction is heated up to to until it is brought to perfect dryness, and may be powdered after refrigeration, or the mixture is dissolved in water and from the solution obtained the dyestuff is precipitated by means of mineral acids or of common salt or by the introduction of a current of carbonic acid or of air. The dark-brownish-green precipitate thus produced is filtered and pressed, the press-cakes are melted with sodium sulfid on the water-bath, and the thick mass is brought to dryness by allowing it to stand in the dry-room or by evaporation on the water-bath. The product obtained by one of these methods is insoluble in alcohol. It dissolves easily in water, forming a bluishgreen-black solution, which on addition of sodium sulfid assumesa more bluish-black coloration. From its aqueous solution the dyestufi is precipitated by means of common salt, mineral acids, or carbonic acid in theshape of a dark brownish-green powder. On addition of caustic-soda lye the color of the aqueous solution remains unchanged. By a sufficient quantity of this latter agent, however, the dyestuff is precipitated, forming a green-black powder. In concentrated sulfuric acid it dissolves slowly, producing a dirty olivegreen solution, which when allowed to repose for several hours or more quickly when heated assumes a bluish coloration. In fuming sulfuric acid of twentythree per cent. SO it dissolves with bluishand dinitrophenol:

2 a I v V v I 647,846

said dye being insoluble in alcohol, easily soluble-in water, forming a green-black solution which on\ addition of sodium sulfid assumes a bluish-black coloration; thedye bein g precipitated from its aqueous solution by means of common salt, of mineral acids or of carbonic acid,'forming a dark brownish-green powder; being precipitated by hot causticsoda lye in the shape of a black powder; being soluble in concentrated sulfuric acid with dirty'olive-green coloration which, when allowed to repose for several hours or more quickly on heating, turns bluish; likewise soluble in fuming sulfuric acid of twentythree per cent. SO with bluish-black coloration; both solutions yielding green-black precipitates on dilution with ice or ice-water; the new coloring-matter dyeing unmordanted cotton'directly deep-black shades.

In witness whereof we have hereunto signed our names,-this 21st day of December, 1899,

in the presence of two subscribing witnesses.

[RICHARD KIROHHOFF. EMIL HAUSSMANN.

- \Vitnesses:

v WoLnEMAR HAUPT,

HENRY HASPER. 

